Flexible thermoelectric devices including a flexible heat management layer on the hot side thereof, and methods of making and using the same, are provided. The flexible heat management layer includes a water harvesting material configured to absorb water or moisture and dissipate heat by evaporation of the absorbed water or moisture. In some cases, the water harvesting material includes a mixture of a superabsorbent polymer (SAP) material and a metal-organic framework (MOF) material.